skip to main content

PI-RADS — MSRA MCQ

Instant feedback + full explanation. One question, done properly.

HardPI-RADSMSRA

A 62-year-old man is investigated on the suspected prostate cancer pathway. He would be suitable for radical treatment if clinically significant prostate cancer were diagnosed. His PSA is 5.6 micrograms/L, MRI-derived prostate volume is 50 mL (PSA density 0.11 ng/mL/mL), and digital rectal examination is benign. He has not previously had a prostate biopsy. Multiparametric MRI demonstrates an 11 mm focal lesion in the right posterolateral peripheral zone. It is mildly hypointense on the ADC map and mildly hyperintense on high-b-value diffusion-weighted imaging. Dynamic contrast-enhanced imaging shows focal early enhancement corresponding to this lesion. There is no extracapsular extension. The radiologist's overall clinical assessment is Likert 4. Which reporting conclusion and immediate diagnostic management step is most appropriate?

Educational content. Not a substitute for clinical judgement or local policy.

Reveal the answer and explanation

Correct answer: C — Report PI-RADS 4 and arrange an MRI-influenced prostate biopsy.

Explanation lettering: E = shown as A · C = shown as B · A = shown as C · B = shown as D · D = shown as E

This is a peripheral-zone lesion, where DWI is the dominant PI-RADS v2.1 sequence. The focal mild diffusion restriction described is DWI score 3 (equivocal), rather than the marked restriction required for DWI score 4. However, focal early enhancement corresponding to an equivocal peripheral-zone lesion is DCE-positive and upgrades the overall PI-RADS category from 3 to 4. The stated Likert 4 assessment independently places him in the NICE group for MRI-influenced biopsy: NICE recommends this for a Likert score of 3 or more. His PSA density of 0.11 does not justify surveillance because the 0.15 ng/mL/mL threshold is relevant to assessing residual concern after a low-suspicion MRI (Likert 1 or 2), not to avoiding biopsy after a Likert 4 scan. B misses the peripheral-zone DCE upgrade. C incorrectly applies the low-suspicion MRI surveillance pathway despite a Likert 4 lesion. D is attractive because biopsy is indicated, but NICE specifies MRI-influenced biopsy for Likert 3 or above rather than a non-targeted systematic approach. E incorrectly treats focal equivocal diffusion restriction with concordant early enhancement as a low-suspicion lesion.

Reference: NICE NG131: Prostate cancer: diagnosis and management, MRI and biopsy recommendations (2019; amended 2021) — https://www.nice.org.uk/guidance/ng131/chapter/Recommendations PI-RADS v2.1: What has changed and how to report (2021) — https://pubmed.ncbi.nlm.nih.gov/34230862/ Investigating the role of DCE-MRI, over T2 and DWI, in accurate PI-RADS v2 assessment of clinically significant peripheral zone prostate lesions (2018) — https://pubmed.ncbi.nlm.nih.gov/30361870/